1/* Copyright (C) 1996-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18/* Declaration of types and functions for "shadow" storage of hashed
19 passphrases. The shadow database is like the user database, but is
20 only accessible with special privileges, so that malicious users
21 cannot retrieve everyone else's hashed passphrase to brute-force at
22 their convenience. */
23
24#ifndef _SHADOW_H
25#define _SHADOW_H 1
26
27#include <features.h>
28
29#include <paths.h>
30
31#define __need_size_t
32#include <stddef.h>
33
34#include <bits/types/FILE.h>
35
36/* Paths to the user database files. */
37#define SHADOW _PATH_SHADOW
38
39
40__BEGIN_DECLS
41
42/* A record in the shadow database. */
43struct spwd
44 {
45 char *sp_namp; /* Login name. */
46 char *sp_pwdp; /* Hashed passphrase. */
47 long int sp_lstchg; /* Date of last change. */
48 long int sp_min; /* Minimum number of days between changes. */
49 long int sp_max; /* Maximum number of days between changes. */
50 long int sp_warn; /* Number of days to warn user to change
51 the password. */
52 long int sp_inact; /* Number of days the account may be
53 inactive. */
54 long int sp_expire; /* Number of days since 1970-01-01 until
55 account expires. */
56 unsigned long int sp_flag; /* Reserved. */
57 };
58
59
60/* Open database for reading.
61
62 This function is not part of POSIX and therefore no official
63 cancellation point. But due to similarity with an POSIX interface
64 or due to the implementation it is a cancellation point and
65 therefore not marked with __THROW. */
66extern void setspent (void);
67
68/* Close database.
69
70 This function is not part of POSIX and therefore no official
71 cancellation point. But due to similarity with an POSIX interface
72 or due to the implementation it is a cancellation point and
73 therefore not marked with __THROW. */
74extern void endspent (void);
75
76/* Get next entry from database, perhaps after opening the file.
77
78 This function is not part of POSIX and therefore no official
79 cancellation point. But due to similarity with an POSIX interface
80 or due to the implementation it is a cancellation point and
81 therefore not marked with __THROW. */
82extern struct spwd *getspent (void);
83
84/* Get shadow entry matching NAME.
85
86 This function is not part of POSIX and therefore no official
87 cancellation point. But due to similarity with an POSIX interface
88 or due to the implementation it is a cancellation point and
89 therefore not marked with __THROW. */
90extern struct spwd *getspnam (const char *__name);
91
92/* Read shadow entry from STRING.
93
94 This function is not part of POSIX and therefore no official
95 cancellation point. But due to similarity with an POSIX interface
96 or due to the implementation it is a cancellation point and
97 therefore not marked with __THROW. */
98extern struct spwd *sgetspent (const char *__string);
99
100/* Read next shadow entry from STREAM.
101
102 This function is not part of POSIX and therefore no official
103 cancellation point. But due to similarity with an POSIX interface
104 or due to the implementation it is a cancellation point and
105 therefore not marked with __THROW. */
106extern struct spwd *fgetspent (FILE *__stream);
107
108/* Write line containing shadow entry to stream.
109
110 This function is not part of POSIX and therefore no official
111 cancellation point. But due to similarity with an POSIX interface
112 or due to the implementation it is a cancellation point and
113 therefore not marked with __THROW. */
114extern int putspent (const struct spwd *__p, FILE *__stream);
115
116
117#ifdef __USE_MISC
118/* Reentrant versions of some of the functions above.
119
120 These functions are not part of POSIX and therefore no official
121 cancellation point. But due to similarity with an POSIX interface
122 or due to the implementation they are cancellation points and
123 therefore not marked with __THROW. */
124extern int getspent_r (struct spwd *__result_buf, char *__buffer,
125 size_t __buflen, struct spwd **__result)
126 __attr_access ((__write_only__, 2, 3));
127
128extern int getspnam_r (const char *__name, struct spwd *__result_buf,
129 char *__buffer, size_t __buflen,
130 struct spwd **__result)
131 __attr_access ((__write_only__, 3, 4));
132
133extern int sgetspent_r (const char *__string, struct spwd *__result_buf,
134 char *__buffer, size_t __buflen,
135 struct spwd **__result)
136 __attr_access ((__write_only__, 3, 4));
137
138extern int fgetspent_r (FILE *__stream, struct spwd *__result_buf,
139 char *__buffer, size_t __buflen,
140 struct spwd **__result)
141 __attr_access ((__write_only__, 3, 4));
142#endif /* misc */
143
144
145/* The simple locking functionality provided here is not suitable for
146 multi-threaded applications. */
147
148/* Request exclusive access to /etc/passwd and /etc/shadow. */
149extern int lckpwdf (void) __THROW;
150
151/* Release exclusive access to /etc/passwd and /etc/shadow. */
152extern int ulckpwdf (void) __THROW;
153
154__END_DECLS
155
156#endif /* shadow.h */
157